#include<bits/stdc++.h> #define N 5010 using namespace std; struct node { double x,y,z; } b[N],a[N]; node O; int n; double R, ans1, ans2, ans3; double sqr(double x) { return x * x; } double dis(node x, node y) { return sqrt(sqr(x.x - y.x) + sqr(x.y - y.y)); } bool incircle(node x) { ...